Some modern business form bursters, such as disclosed in copending applications Ser. No. 08/020,537, filed Feb. 22, 1993, and Ser. No. 08/123,971 filed Sep. 21, 1993, are utilized to burst mid-form slit and collated business forms. These business forms, because of the mid-form slitting and 50% offset of leading edges of each web (two or more webs one on top of the other are provided) present a problem with regard to proper feeding to the burster. Oftentimes the top web does not feed properly through the slow roll section of the burster, resulting in poor operation, torn webs, or other adverse consequences.
In order to correct the problem discussed above, according to the present invention a plurality of puller wheels are associated with the conveyor belts which transport the offset continuous collated business forms to the burster. The puller wheels are mounted atop some of the conveyor belts at the point which those conveyor belts pass over crowned pulleys, the conveyor belts driven by a powered rubber covered transport roll upstream of the crowned pulleys. An apertured rigid plate also is provided above the conveyor belts and pulleys, with the puller wheels' external surfaces extending through the apertures into contact with the forms. The puller wheels have a rigid (aluminum) core and a resilient material (rubber) covering that has a sawtooth configuration, so that the puller wheels may be oversped relative to the business form speed without causing excessive pull on the webs themselves. In this way offset collated forms are properly fed to the slow rolls of a burster having slow roll and fast roll sections.
The puller wheels may cause the conveyor belts to run off the crowned pulleys. In order to preclude this, a conveyor belt aligner is provided. The conveyor belt aligner includes an idler roller disposed on each side of each conveyor belt associated with a crowned pulley and pulley wheel. The idler rolls may be formed by metal dowel pins which extend generally vertically (perpendicular to the axis of the drive roller for the conveyor belts) and are covered by plastic sleeves which may rotate with respect to the dowel pins (are loose fitting). At least one of the dowel pins, with associated sleeve, may be provided between two conveyor belts, aligning both. All the dowel pins may be mounted on an aluminum bar which is positioned adjacent (e.g. just upstream of and below) the powered rubber covered transport roll.
Utilizing the apparatus described above, according to another aspect of the present invention a method of feeding offset continuous collated business form webs to a burster having slow rolls and fast rolls is provided. The method comprises the steps of: (a) Feeding the webs in a first direction at a first speed. (b) Engaging one of the webs with a plurality of puller wheels driven at a second speed greater than the first speed, in such a way that excessive pull of the web does not occur. And (c) directing the webs from the puller wheels directly to the burster so that all webs are reliably fed between the slow rolls of the burster.
Step (a) is typically practiced by conveyor belts which pass over crowned pulleys, and step (b) is practiced by providing a sawtooth resilient material covering the puller wheels. There is also the step (d) of positively preventing the conveyor belts from running off the crowned pulleys associated with the puller Wheels, the step (d) being practiced by providing idler rollers on opposite sides of each of the conveyor belts associated with a crowned pulley with puller wheel.
It is a primary object of the present invention to effect the proper feeding of offset collated business forms to the slow roll section of a burster. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.